DE19836253C1 - Polymethacrylate-polyalkylene oxide block copolymers, useful as dispersants and compatibilisers in printing ink, paint and plastics formulations - Google Patents

Abstract

Polymethacrylate ester-polyalkylene oxide block copolymers with terminal carboxylic acid or carboxylate groups. Polymethacrylate ester-polyalkylene oxide block copolymers of formula (I) with terminal carboxylic acid groups, in which R<1> = the residue of a known chain regulator or initiator with no reactive hydrogen atoms; R<2> = 1-22C alkyl, or optionally substituted aryl, perfluoroalkyl or dialkylamino; R<3> = 1-4C alkyl or phenyl; R<4> = an organic residue with at least one carboxylic acid or carboxylate function; X = O or NH; a = 4-20; b = 20-100; c = 0-20; b/c = at least 4 . An Independent claim is also included for aqueous pigment preparations containing inorganic or organic pigment(s) and block copolymer(s) (I) as dispersant.

Description

The invention relates to polymethacrylic acid esters with poly transesterified ether diols or amidated with polyether diamines and then be functionalized and their use as a dispersant for the preparation of aqueous pigment preparations ions.

To disperse solids in liquid media lightening and improving are usually dispersing used agents that also stabilize the dispersions obtained should act and a re-agglomeration or to prevent flocculation of the solid particles. The Tues Detergents promote Benet as surface-active agents tion of the solid particles to be dispersed and facilitate breaking up agglomerates.

They are of particular importance, for example, for Tues pigmentation in the manufacture of printing inks, Paints and varnishes and in the pigmentation of art masses of fabric.

In addition, special dispersants can be used as Compatibi lizer the compatibility between chemically different Increase polymer types. This is e.g. B. for the production of SMC or BMC molding compounds of particular importance.

Wetting and dispersing agents facilitate the incorporation of pigments and fillers in the manufacture of paints and varnishes, which, as important formulation components, significantly determine the visual appearance and the physicochemical properties of coatings. For optimum use, these solids must firstly be evenly distributed in paints and varnishes, and secondly, the distribution once achieved must be stabilized. Numerous problems can now arise during the production and processing of aqueous pigment pastes:

• - difficult incorporation of the pigments, poor wetting
• - high viscosities of color pastes, paints and varnishes
• - sediment formation
• - vertical floating of pigments (flooding)
• - horizontal floating of pigments (floating)
• - low degree of gloss
• - low hiding power
• - insufficient color strength
• - poorly reproducible color tones, color shift
• - Lacquers are too prone to run off

There is therefore no shortage of attempts to find effective dispersion additives for solids, especially pigments len. For example, water-soluble, hydrophilic poly polyisocyanate addition products containing ether chains (EP-A- 0 731 148), acidic poly (meth) acrylates (US-A-3 980 602, WO-A- 94/21701), phosphate ester of polyalkylene oxide block polyesters (WO-A-97/19948) or alternating copolymers of vinyl monomers ren and dicarboxylic acid diesters (WO-A-96/14347, EP-A-0 791 024), in particular copolymers based on maleic acid derivatives and Vinyl monomers described for this purpose.

However, with the use of such products there are also a multitude of disadvantages. So are often high levels of Di Spergieradditiv additions required, the achievable Pigmen Heights of the pastes are unsatisfactorily low, the sta tity of the pastes and thus their viscosity constancy is un sufficient, flocculation and aggregation can not be in the always avoid; in many cases there is also a lack of color consistency after storage of the pastes and compatibility with diver binders. Through the use of known dispersing additives  In many cases, water resistance or Light resistance of coatings negatively affected, moreover the resulting in the manufacture and processing wanted foam additionally stabilized. Also - is conditional due to poor compatibility of the dispersing resins in many Auflackgüter - often in an undesirable way the gloss be impaired.

Especially the phosphoric acid esters from amphiphilic block copo Lymeren are the phosphorus due to insufficient hydrolysis stability marked ester grouping. Also the water resistance coatings produced with this are adversely affected. In addition, these acidic phosphoric acid esters usually require an undesirable amine-based additive in the required amount sentence to z. B. the optimized pH of a coating system put.

The present invention is therefore based on the object to overcome a variety of the disadvantages mentioned, the important viscosity stability of the Pa most, the avoidance of flocculation and aggrega tion, the color consistency after storage of the pastes and the Water resistance of coatings made from it positive should be influenced.

In addition, compatibility with these products is said chemically incompatible substances can be improved.

The object is surprisingly achieved according to the invention by dispersants based on block-polymethacrylic acid ester-block-polyalkylene oxide copolymers with terminal carboxylic acid of the general formula I.

in which
R ^{1 is} the residue of a chain regulator or initiator known per se which is free of active hydrogen atoms,
R ^{2 are the} same or different and are alkyl radicals having 1 to 22 carbon atoms or optionally also substituted aryl radicals, perfluoroalkyl or dialkylamino radicals,
R ^{3 are the} same or different and are alkyl radicals having 1 to 4 carbon atoms or phenyl radicals,
R ^{4 represents} an organic radical with at least one carboxylic acid or carboxylate function,
X is oxygen or NH,
a a value from 4 to 20,
b a value from 20 to 100 and
c has a value from 0 to 20, the ratio b / c <= 4.

The rest R ¹ is a chain regulator or initiator known per se. Azo compounds or peroxides may be mentioned as examples of the prior art. Examples of chain regulators are mercaptans, chloroform, isopropylbenzene or isopropanol. The radical -SC ₁₂ H ₂₅ is preferred for R ¹ . Further examples of residues resulting from the chain regulator are the residue derived from tert-dodecyl mercaptan and the octadecyl and tetradecyl mercaptan residue.

R ² is preferably a methyl or butyl radical. Examples of suitable perfluoroalkyl radicals are the trifluoroethyl, penta fluoropropyl, nonafluorohexyl and the tridecafluorooctyl radical.

X is an oxygen atom if you look at α, ω-polyalkoxy ether diols uses, and an NH group, if you have α, ω-polyether diamines used.

R ³ is an alkyl or aryl group, preferably a methyl or phenyl group.

The indices b and c can be the same or different and b is usually in the range from 20 to 100 and c in the range from 0 to 20. The ratio of b: c is included preferably ≧ 4. The different alkoxy units can in blocks or also statistically in the polyalkoxy chain be installed. Examples of suitable alkoxylating agents are ethylene carbonate, propylene carbonate, styrene oxide, butylene oxide, especially propylene oxide and especially ethylene oxide and their mixtures.

The radical R ⁴ contains at least one carboxylic acid or at least one carboxylate unit. Examples of R ⁴ are all products that result from the reaction of an alcohol with anhydrides. Preferred anhydrides are succinic anhydride, maleic anhydride, phthalic anhydride or trimellitic anhydride. The analog half-amide compounds form analogously for the case X = NH.

Examples for R ⁴ :

Z is a cation. Z is preferably an alkali or ammonium radical, which can optionally be alkyl-substituted. Examples of such substituted ammonium radicals are the radicals NH (CH ₃ ) ₃ -, NH (C ₂ H ₅ ) ₃ - and NH (CH ₂ -C ₆ H ₅ ) (CH ₃ ) ₂ . In addition, the cations known from the prior art for carboxylic acid groups can be selected (eg neutralization with amines or amino alcohols, such as triethanolamine, aminomethylpropanol or dimethylethanolamine).

Examples of block copolymers according to the invention are:

For the production of such block copolymers with a terminal car bonic is the block polymethacrylic acid ester block Polyalkylene oxide copolymer with terminal hydroxy or amino group produced and then anionically endfunctional siert.

The production of polymethacrylate block with polyalkylene oxide terminal hydroxy group is known from the literature. For example is in Macromolecules (1992), 25 (25), 6733-6738, Polym. J. (1980), 12 (3), 183-192, in the patent literature (DD-C- 0 221 742) or in Makromol. Chem., Rapid Commun. (1984), 5 (9), 615-618 on the preparation of such block copolymers anionic polymerization of methyl methacrylate and ethylene oxide using organolithium initiators. Large-scale such procedures are hardly feasible. On the one hand, one extremely high demands on the purity of the reactants and  any solvent used, the other who usually need very low reaction temperatures (around -78 ° C) does. The use of special, sensitive alkali metal initiates gates (potassium naphthalide or diphenylmethyl potassium) difficult the implementation of the reaction additionally.

Alternatively, block copolymers based on polyalkylene oxide and methacrylate monomers, by redox polymerization Base of Ce4 +. In the literature is about that a variety of examples listed, such as. B. in Angew. Macromol. Chem. (1997) 245, 9-22. The main disadvantage of this reaction is that cerium (IV) ammonium nitrate is very expensive and in equimola Ren amounts must be used. It also has a very high one Molecular weight (MW 548.23), resulting in one mole of PEG3000 already about 1.1 kg of cerium (IV) ammonium nitrate are used ought to.

The easiest way to prepare block polymethacrylic acid To produce ester block polyalkylene oxide copolymers is in EP-A-0 613 910. There is the end group transesterification of polymethacrylic acid esters with various alcohols described. In principle, this method is not only for mono alcohols limited, but it can also be dihydroxy-functional Compounds are used, as already in EP-A-0 622 378 has been described.

However, none of these patents include a further implementation of the terminal hydroxy groups with anhydrides to polymethacrylic acid reester block polyalkylene oxide compounds with terminal carb oxyfunction have been described. Surprisingly, ge found that the desired end-functionalized block copoly by a one-pot reaction in a very simple manner can be put.

Here, a radical polymerization is carried out first Presence of a chain regulator obtained polymethacrylic acid  esters with α, ω-difunctional polyethers at temperatures of 70 to 150 ° C, preferably 100 to 120 ° C transesterified. The Re action can be carried out with or without solvent. In Usually, any existing ones are removed first Traces of moisture with an inert solvent, as with for example toluene or xylene, residues of water from the system away. In order to remove the Al alcohol (depending on the polymethacrylate used e.g. methanol or Butanol) is easier to remove from the reaction mixture the addition of an inert solvent such as toluene, xylene or a gasoline fraction with a boiling range of 70 to 140 ° C recommendable. State-of-the-art Lewis Transesterification catalysts, such as, for example, alkyl titanate, Alkyl zirconate, dialkyltin acetate halide or dialkyl Tin dialkyl esters, in amounts of 0.1 to 3 wt .-%, bezo gene on the polymethacrylic acid ester. Especially Suitable catalysts are isopropyl titanate and dibutyl tin acetate chloride or dibutyltin oxide. The molar ratio from polymethacrylic acid ester to polyalkylene oxide can be 1: 0.5 to 1: 3, preferably 1: 1. The main side reaction is that Formation of the triblock copolymer polymethacrylic acid ester block Polyalkylene oxide block polymethacrylic acid ester that is not made the reaction mixture is removed. The share of the by-product tes is strongly from the polymethacrylic acid ester / polyalkylene oxide Ver ratio influenced. The turnover can a. by OH number determination be followed.

After complete conversion, the anionic modification in done in a known manner. To do this, the corresponding Anhydride added and the reaction mixture at a temperature rature from 70 to 150 ° C, preferably 100 to 120 ° C, heated. The molar ratio of anhydride to hydroxy groups present can 2: 1 to 1:10, preferably 1: 1. All commercial Available anhydrides can be used. Suitable Anhydrides are e.g. B. succinic anhydride, maleic anhydride drid, phthalic anhydride or trimellitic anhydride. The end  the reaction can at the disappearing OH and emerging Acid number can be determined. Others state of the art corresponding acylating agents, such as acid halides or Esters, can be used.

The preparation of the block polymethacrylic acid ester block polyal kylene oxide copolymers with terminal carboxylic acid for use as a dispersant for aqueous pigment pastes is in the following examples explained in more detail.

Example 1A Manufacture of polymethyl methacrylate by radical poly merization (not according to the invention)

In a reactor, 180 g of toluene are heated to 100 ° C. under a nitrogen atmosphere. A solution of 4.2 g of azodiisobutyronitrile, 202.4 g of n-dodecyl mercaptan (1 mol) and 1198 g (approx. 12 mol) of methyl methacrylate in 170 g of toluene is added dropwise at a constant rate at 100 ° C. in the course of 3 hours. After the reaction has ended, the addition of 2.8 g of azodiisobutyronitrile takes place within 1 hour and the mixture is then left to react for a further 1 hour. Residual monomers and solvents are removed at 150 ° C. in an oil pump vacuum (1 torr) and the clear, viscous product is diluted to a solids content of 70% by adding toluene. From the gel chromatographic examination, the M _n value (calibration against PMMA / THF) of 1710 for an obtained polymer was obtained with an M _w / M _n ratio of 1.56. The residual monomer content is <0.1%.

Examples 2A and 3A Production of polymethyl methacrylates with different Molecular weights by radical polymerization (not he according to the invention)

The procedure is basically the same as in Example 1A with the Un differed that, as shown in Table 1, the amount of n-Dodecyl mercaptan and the amount of initiator vary.

Table 1

Example 4A Production of poly-n-butyl methacrylate by radical Po lymerization (not according to the invention)

The procedure is basically the same as in Example 1A with the Un differed that instead of 12 molar equivalents of methyl methacrylic now 10 molar equivalents of n-butyl methacrylate per 1 mol of n-dode cylmercaptan can be used.

From the gel chromatographic investigation, the M _n value (calibration against PMMA / THF) of 2150 for an obtained polymer was obtained with an M _w / M _n ratio of 1.78. The residual monomer content is <0.1%.

Example 5A Production of a polystyrene block-polyalkylene oxide copolymer (not according to the invention; analogous to DE-A-41 34 967)

100 g of xylene are mixed in a nitrogen atmosphere heated to 120 ° C with a stirrer reactor. To within 3 hours while maintaining the temperature from 120 ° C a mixture of 2288 g (about 22 mol) of styrene, 78 g (1 mol) 2-mercaptoethanol, 4.1 g azodiisobutyronitrile and 310 g of xylene. After the addition is complete an after-reaction of about 15 minutes; then be 0.16 g of methyl hydroquinone added.

Excess monomer, Xy lol and residual amounts of 2-mercaptoethanol removed and the lead Colorless, viscous product with xylene on egg diluted solids content of about 80%.

The determination of the hydroxyl number gives a molecular weight M _n of 1100 g / mol. A value of 1200 g / mol is obtained from the vapor pressure osmometric molecular weight determination. From the gel chromatographic examination, the M _n value (calibration against polystyrene / THF) for the polymer obtained is 1175 with an M _w / M _n ratio of 1.75. The residual monomer content is <0.1%.

The solution of 1100 g (about 1 mole) of the ω-hydroxy functional Polystyrene in 200 g xylene and 35.0 g potassium methylate (approx 0.5 mol) are in a well-dried stainless steel reactor give, which is also provided with a stirrer. By Azeotropic distillation is both traces of water as well Removed methanol along with xylene. Then a tem temperature of 80 ° C and about 3000 g of ethylene oxide (about 70 mol) was added with stirring so rapidly that the reactor temperature does not exceed 85 ° C. After more complete  100 g of water are added to the introduction and then with 30% phosphoric acid brought to a pH of 6 to 7. The The water is removed by azeotropic distillation in the Vacuum and that of the precipitated salt by filtration.

The molecular weight determined from the determination of the hydroxyl number with an assumed functionality of 1 is 13.8 mg KOH / g polymer; the gel permeation chromatogram shows only one maximum and gives a value of 2880 for M _n (calibration against polystyrene), and 1.21 is obtained for the ratio M _w / M _n .

Examples 1B to 4B (not according to the invention)

The in the inventive and non-inventive Bei Play used polyether diols, starting from Ethy lenglycol as starting alcohol, through alkaline-catalyzed homo polymerization of 70 or 55 moles of ethylene oxide or starting of propylene oxide, by blocks, also alkaline kata lysed copolymerization of propylene oxide (12 or 17 mol) and Ethylene oxide (55 and 23 moles) produced.

Table 2

Example 1C Production of block polymethacrylic acid ester block polyalky lenoxide copolymers (not according to the invention)

1400 g (approx. 1 mol) of the polymethyl methacrylate from Example 1A (70% solution in toluene), 3000 g (approx. 1 mol) of the polyether from Example 1B are heated to 120 ° C. in a reactor under a nitrogen atmosphere and that Distilled off solvent with simultaneous removal of traces of water. 22 g (0.5% by weight) of isopropyl titanate are then added at 100 ° C. and the methanol formed in the onset of the reaction is distilled off for several hours at 120 ° C. and 2 mm Hg. The course of the reaction can be followed by gas chromatographic analysis of the distillate with regard to the amount of methanol contained, but also by determining the OH number. After about 8 hours the conversion is quantitative and a yellow product is obtained which is solid at room temperature. The OH number is 12.9 mg KOH / g polymer. From the gel chromatographic examination, he obtained an M _n value (calibration against PMMA / THF) of 8730 with an M _w / M _n ratio of 1.15 for the polymer obtained.

Table 3 shows further examples for the synthesis of block Polymethacrylic acid ester block polyalkylene oxide copolymers such as they are obtained by the above manufacturing process.  

Table 3

Example 1D Production of block polymethacrylic acid ester block polyalky lenoxid copolymers with terminal carboxy group (Invention according to)

Immediately following the synthesis of the block polymethacrylic acid ester block polyalkylene oxide 1C, 98 g (approx. 1 mol) Maleic anhydride added at 120 ° C. After about 2 hours the reaction is over. The acid number of the material obtained than is 12.4 mg KOH / g polymer.

Table 4 shows further examples for the implementation of block Polymethacrylic acid ester block polyalkylene oxide copolymers with various anhydrides, such as those according to the above adjustment process can be obtained.  

Table 4

Example 7D Implementation of succinic anhydride (BSA) with polystyrene Block polyalkylene oxide copolymers 5A (not according to the invention)

The anionic modification is carried out analogously to 1D, except that this time directly after the synthesis of 5A 1 mol equivalent of Bern adds rock acid anhydride. After a response time of 2 hours at 120 ° C you can see the end of the reaction from the Determine the acid number of 12.8 mg KOH / g polymer.

Example 8D Production of the phosphoric acid ester of polystyrene block-Po lyalkylene oxide copolymers 5A (not according to the invention)

4100 g (corresponds to 1 OH equivalent) of the block copolymer 5A are placed in the reactor and heated to 120 ° C. after addition of about 200 ml of toluene. By applying a vacuum, all volatile components, in particular any water present in the product, are removed from the reaction space by distillation. After venting with nitrogen, the temperature is raised to 80 ° C. and 85 g of the liquid polyphosphoric acid (0.25 mol P ₄ O ₁₀ ; manufacturer: Merck, content calculated as P ₄ O ₁₀ : approx. 85%) are added. The reaction is complete after 2 hours. The acid number of the material he received is 26.8 mg KOH / g. No aliphatic hydroxyl group can be detected in the ¹ H-NMR spectrum.

Example 9D Preparation of the phosphoric acid ester from polymethacrylic acid ester block polyalkylene oxide copolymers 1C (not fiction according to)

The reaction with polyphosphoric acid is carried out analogously to 8D, except that this time 0.25 mol of P ₂ O _{10 is} added instead of an anhydride directly after the synthesis of 1C. The end of the reaction can be seen from the acid number of 25 mg KOH / g polymer.

To produce aqueous pigment pastes, 0.1 to 100% by weight of the block polymethacrylic acid ester according to the invention Block polyalkylene oxide copolymers with terminal carboxylic acid, preferably 0.5 to 50 wt .-% (based on the weight of the Pigments). The copolymers according to the invention can either mixed in advance with the pigments to be dispersed or directly to the dispersing medium (water, possible Glycol ether additives) before or simultaneously with the addition of Pigments and any other solids are dissolved.

For the production of aqueous, highly concentrated, pump and flow capable pigment preparations is to ver according to the invention turning polymer, optionally in combination with at least another component, mixed with water, in this Mi The pigment is sprinkled in with stirring and until brought up the desired fineness and consistency of the suspension dispersed.

Another method for producing the pig according to the invention ment preparations consists of a pigment with the inventions  copolymers according to the invention are first mixed dry, from which a powdery pigment preparation results. This can if necessary be dispersed in water, the Invention appropriate pigment preparation is obtained.

A third method of making aqueous, highly concentrated ter, pumpable and flowable pigment suspensions and pastes is an aqueous-moist pigment filter cake with the to offset copolymer according to the invention and for example with incorporate a dissolver into the pigment filter cake, whereby this liquefies.

The following may be mentioned as examples of pigments to be dispersed:

• - monoazo pigments:
  CI Pigment Brown 25;
  CI Pigment Orange 5, 36 and 67;
  CI Pigment Red 1, 2, 3, 48: 4, 49, 52: 2, 53, 57: 1, 251, 112, 170 and 184;
  CI Pigment Yellow 1, 3, 73, 74, 65, 97, 151 and 183;
• - diazo pigments:
  CI Pigment Orange 34;
  CI Pigment Red 144 and 166
  CI Pigment Yellow 12, 13, 17, 83, 113 and 126;
• - Anthraquinone pigments:
  CI Pigment Yellow 147 and 177;
  CI Pigment Violet 31;
• - anthrapyrimidine pigments:
  CI Pigment Yellow 108;
• - Quinacridone pigments:
  CI Pigment Red 122, 202 and 20;
  CI Pigment Violet 19;
• - Quinophthalone pigments:
  CI Pigment Yellow 138;
• - Dioxazine pigments:
  CI Pigment Violet 23 and 27;
• - Flavanthrone pigments:
  CI Pigment Yellow 24;
• - Indanthrone pigments:
  CI Pigment Blue 60 and 64;
• - Isoindoline pigments:
  CI Pigment Orange 69;
  CI Pigment Red 260;
  CI Pigment Yellow 139;
• - Isoindolinone pigments:
  CI Pigment Orange 61;
  CI Pigment Red 257 and 260
  CI Pigment Yellow 109, 110, 173 and 185;
• - Metal complex pigments:
  CI Pigment Yellow 117 and 153;
• - Perinone pigments:
  CI Pigment Orange 43;
  CI Pigment Red 194;
• - Perylene pigments:
  CI Pigment Black 31 and 32;
  CI Pigment Red 123, 149, 178, 179, 190 and 224;
  CI Pigment Violet 29;
• - phthalocyanine pigments:
  CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6 and 16;
  CI Pigment Green 7 and 36;
• - Pyranthrone pigments:
  CI Pigment Orange 51;
  CI Pigment Red 216;
• - Thioindigo pigments:
  CI Pigment Red 88;
• - Triphenylmethane pigments:
  CI Pigment Blue 1, 61, and 62;
  CI Pigment Green 1;
  CI Pigment Red 81 and 169;
  CI Pigment Violet 2 and 3;
• - C.I. Pigment Black 1 (aniline black)
• - C.I. Pigment Yellow 101 (Aldazine Yellow)
• - Inorganic pigments:
• - white pigments:
  Titanium dioxide (CI Pigment White 6), zinc white, colored zinc oxide; Zinc sulfide, lithopone; Lead white;
• - black pigments:
  Iron oxide black (CI Pigment Black 11), iron-manganese black, spinel black (CI Pigment Black 27); Carbon black (CI Pigment Black 7);
• - Colored pigments:
  Chromium oxide, chromium oxide hydrate green; Chrome green (CI Pigment Green 48); Cobalt green (CI Pigment Green 50); Ultramarine green;
  Cobalt blue (CI Pigment Blue 28 and 36); Ultramarine blue; Iron blue (CI Pigment Blue 27); Manganese blue;
  Ultramarine violet; Cobalt and manganese purple;
  Iron oxide red (CI Pigment Red 101); Cadmium sulfoselenide (CI Pigment Red 108); Molybdate red (CI Pigment Red 104); Ultra marine red;
  Iron oxide brown, mixed brown, spinel and corundum phases (CI Pigment Brown 24, 29 and 31),
  Chrome orange;
  Iron oxide yellow (CI Pigment Yellow 42); Nickel titanium yellow (CI Pigment Yellow 53;
  CI Pigment Yellow 157 and 164); Chrome titanium yellow, cadmium sulfide and cadmium zinc sulfide, (CI Pigment Yellow 37 and 35);
  Chrome yellow (CI Pigment Yellow 34), zinc yellow, alkaline earth metal chromates, Naples yellow, bis mutvanadate (CI Pigment Yellow 184);
• - gloss pigments:
  Metallic effect pigments based on metal flakes coated with metal oxide; Pearlescent pigments based on mica flakes coated with metal oxide.

Fillers, for example dispersed in aqueous paints can be z. B. those based on kaolin, talc, other silicates, chalk, glass fibers, glass beads or metal powder.

As coating systems in which the pigment preparation according to the invention can be lacquered, any aqueous 1K or 2-component paints. Examples include aqueous ones 1-component paints, such as those based on alkyl, acrylic lat, epoxy, polyvinyl acetate, polyester or polyurethane resins, or aqueous 2-component paints, for example those based of hydroxyl-containing polyacrylate or polyester resins with melamine resins or optionally blocked polyisocya natharzen as a crosslinker. In the same way, poly called epoxy resin systems.

Water is the preferred solvent for the invention Copolymers. But also organic solvents, such as Wise glycol ethers or esters, alone or in a mixture can be used with water. Especially for drying behavior of the copolymers according to the invention pigment pastes is the addition of solvents in many cases advantageous.  

Can be used to produce the pigment preparations according to the invention also the addition of other non-inventive water dispersible polymers, such as polyacrylate, Polyurethane or polysiloxane derivatives are used.

In the production of the pigment preparations according to the invention can also use other aids, such as defoamers, preserves aids, wetting agents, deaerators or the status of Technically appropriate anti-settling agents, waxes or rheolo find additional use.

The block polymethacrylic acid ester block polyalkylene oxide carboxylic acids used as dispersants for aqueous pigment pastes are described according to general formula I. The indices a, b and c and the radicals R ¹ to R ⁴ and X have the meanings or values shown in the table below.

Production of pigment pastes

To produce the pigment pastes, the inventive (1 to 5) and non-inventive (6 to 10) dispersing addi tive 40% pre-dissolved in water, with water and additives mixed and then added the pigments. The dispersion after adding grinding media (glass balls 2 to 3 mm, same volume as the pigment paste) 1 (titanium dioxide) or 2 h (other pigments) in a Skandex vibrator with air cooling.  

Formulation of the white pastes

The white pastes are formulated as follows (data in% by weight):
16.4 water
12.3 additive solution, 40%
1.0 defoamer (e.g. Tego Foamex 810, Tego Chemie Service GmbH)
70.0 Titanium dioxide 2160 (Kronos)
0.3 Aerosil A 200 (Degussa)

Formulation of black pastes

The black pastes are formulated as follows (data in% by weight)
60.3 water
22.3 additive solution, 40%
1.0 defoamer (e.g. Tego Foamex 810, Tego Chemie Service GmbH)
1.4 AMP 90 (Angus)
15.0 color soot FW 200 (Degussa)

Test paints

Stoving clear varnish based on a modified alkyd resin (in% by weight)
70.88 Resydrol VWA 5477, 40% (Hoechst)
0.14 defoamer (e.g. Byk 020, Byk-Chemie)
0.68 Bentone SD 1 (Rheox)
8.24 Maprenal MF 900 (Hoechst)
0.14 triethanolamine
19.10 water
0.68 Additol XW 395 (Hoechst)
0.14 Additiol XW 329
Place position 1 and add the other components while stirring.

Dispersion clear coat

97.0 Neocryl XK 90 (Zeneca)
3.0 Texanol

For the production of gray pigmented lacquers, 40.0 g of clear are used submitted paint, 14.2 g of white paste and 2.65 g of black paste given and homogenized at 1500 rpm for 5 min. The samples will be with 100 µm wet film thickness on aluminum sheets and either baked for 15 min at 150 ° C after 20 min flash-off time (Stove enamel) or dried at room temperature (dispersion paint).

Paste stability test

To determine the paste stabilities, two are different which shear rate (20 1 / s and 1000 1 / s) the achievable Initial viscosities as well as the viscosities after four weeks Storage at 50 ° C determined.  

White pastes

Black pastes

From the only slight increase in viscosity, the good stability of the pigment pastes according to the invention know. When using the non-inventive block copoly merisates 10 could not store pigment concentrates that were stable in storage be formulated.

Dispersion test

The test formulations are coated with a 100 µm wet film thickness gene; after drying for six minutes, a rub-out test is carried out 1/3 of the coated area. After baking or drying Colorimetric measurements are performed overnight after every 24 hours Measurement of the elevators using a spectrophotometer type XP 68 from X-Rite. The determinations of gloss level and -Veils are made using the company's Haze-Gloss device Byk-Gardner.  

Stoving varnish based on Resydrol VWA 5477

Dispersion varnish based on Neocryl XK 90

This can be seen through the use of the invention Dispersion additives achievable favorable color strength development as well as the rub-out test, which is cheap in all cases.

Water resistance test

The branded (System Resydrol) or 7 days at room temperature air-dried (system Neocryl) gray pigmented Lacquer films are exposed to standing water for 20 hours and then for surface defects (blistering / hue ver shift) and softening.  

The active compounds according to the invention lead - especially in ver same to analog phosphoric acid esters - not one leg impairment of the water resistance of the paint films.

As can be seen from the previous comparisons, NEN the compounds to be used according to the invention their universal applicability, the ease of manufacture stable pigment pastes, achievable pigmentation levels, er achievable color stability and achievable improvements the water resistance of lacquered coatings.

Claims (9)

1. Block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid of the general formula I
in which
R ^{1 is} the residue of a chain regulator or initiator known per se which is free of active hydrogen atoms,
R ^{2 are the} same or different and are alkyl radicals having 1 to 22 carbon atoms or optionally also substituted aryl radicals, perfluoroalkyl or dialkylamino radicals,
R ^{3 are the} same or different and are alkyl radicals having 1 to 4 carbon atoms or phenyl radicals,
R ^{4 represents} an organic radical with at least one carboxylic acid or carboxylate function,
X is oxygen or NH,
a a value from 4 to 20,
b a value from 20 to 100 and
c has a value from 0 to 20, the ratio b / c <= 4. 2. Block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid according to claim 1, characterized in that R ^{2 is} an alkyl radical having 1 to 4 carbon atoms. 3. Block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid according to claim 1, characterized characterized in that X is oxygen.   4. Block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid according to claim 1, characterized characterized in that the value of c is 0. 5. Block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid according to claim 1, characterized characterized in that the value of a is 6 to 15. 6. block polymethacrylic acid ester block polyalkylene oxide copoly meres with terminal carboxylic acid according to claim 1, characterized in that R ^{4 represents} an aliphatic radical, in particular re the radical -C (O) CH ₂ CH ₂ COOH. 7. Aqueous pigment preparation containing at least one anor ganic or organic pigment and at least one block Polymethacrylic acid ester block polyalkylene oxide copolymer with terminal carboxylic acid according to claim 1 to 6 as di detergents. 8. Aqueous pigment preparation containing 1 to 100 wt .-%, be pulled on pigments, on dispersing additives according to the claims Chen 1 to 6. 9. Use of the block polymethacrylic acid according to the invention terminal block polyalkylene oxide copolymers with car bonic acid as a tolerance mediator in SMC or BMC Wording.